Zoysia club roots?

i was bidding a zoysia Lawn the other day and ran across this.
The dead area started last summer and progressed. I am pretty certain it was cinch bugs by the looks of it, and his description of how it progresses. But wondering about the stunted/club roots? Would they be caused by a pre emergent earlier in spring, or a herbicide applied during or after cinch bug damage occurred?

More interested in the club/stunted roots than the large dead area.
I have seen it before in lawns with no apparent pests but obvious fungal issues. Wondering if the herbicide damage is expressed more when other factors are at play.

Failure to respond to Nitrogen in absence of confounding factors such as salinity and/or pH is diagnostic for me. So is wilting in spite of adequate soil moisture. Another is weeds taking over the area. Heavy usage of preemergent will mask the tendency for weeds to take over but will encourage large areas to become dirt. The weeds I see taking over in high nematode soils include Crabgrass, Goosegrass, Prostrate Spurge, Nutsedge, and Kyllinga species. Normally, Zoysia develops such a dense root system that weeds are incapable of establishing.

I attended a seminar on nematodes in golf turf 2 months ago. The takeaway point from that seminar was that nematode assays done on soils mostly find live nematodes in the process of attacking roots. They are not as good at finding nematodes when they have already caused severe damage because nematodes need a live host. Dead grass is not a good host. If that were mine to deal with, I would be treating it with Fluopyram when conditions are ideal for growth of the Zoysia to resume.

This is becoming an issue due to Diazinon being illegal for turf application for the last 18 years. I noticed it in Hawaii. Tifdwarf, Tifgreen and Tifway 419 are very hard to keep here. Empire and El Toro Zoysia is also hard to keep here. In some lawns the Zoysia is very vigorous and requires usage of PGRs to make them maintainable. In other lawns, they are fragile and prone to dying off.

Glad you said that. That symptom is synonyms with root rot also. Often root rot & nematode are mixed together causing this dominate symptom. Easy to miss diagnose which one is forefront. Most won't think about nematode first. But will apply expensive fungicides a couple of times with little effect. Then dig for insect activity. Then apply insecticide. All the while nematode's have left evidence.

Thanks. I did suspect nematodes, but last year I had sent a sample from a different property to Mississippi state diagnostic lab, per the county agent citing herbicide damage. I do not know the history of the Lawn.

My challenge to nemotodes is the consistency of the affected area. Do nematode symptoms not appear more sporadic? Though there is the same club root in the front lawn with sporadic patterns, the back is one larger continuous area.

Also, does anyone have pictures of confirmed nematode damage in a residential turf? Or at least not mown like a green.
What criteria do you base having an assay done vs just applying a corrective measure?

Also, does anyone have pictures of confirmed nematode damage in a residential turf? Or at least not mown like a green.
What criteria do you base having an assay done vs just applying a corrective measure?

Click to expand...

Probably cost.
Here in Arkansas, we can take samples to be tested to our Extension Office and they send it off to the U of A and for $10.00 you can find out. I have a specific neighborhood that several houses in the neighborhood had problems with nematodes. When I was dealing with the one I was dealing with, I was told that for the most part, nematicides had been taken off the market due to there toxicity to the environment. I researched it and farmers plant mustard greens to keep nematode populations low. Unfortunately, I can't plant mustard greens in my lawns. It was suggested to go easy on fert, use organic blends if possible and aerate. I could not find ground mustard greens or seeds to spread so I aerated the ever loving piss out of the lawn and used organic ferts sparingly and believe it or not, the problem went away. These were stinging nematodes with a threshold count at around 600. I'm sure the product Greendoctor speaks of has a fairly high cost...just guessing though.

"Opportunity is missed by most because it is dressed in overalls and looks like work"- Thomas Edison, businessman/inventor